Strip-feeding mechanism for sewing machines



Oct. 8, 1929. K. MAIER STRIP FEEDING MECHANISM FDR SEWING MACHINES Filed Nov. 26, 1927 Patented 0a. 8, 1929 UNITED STATES PATENT OFFICE KARL MAIEB, OF STUTTGABT, GERMANY, ASSIGNOB TO UNION SPECIAL MASCHINEN- IABBIK, G. M. B. 3., OF STUTTGABT, GERMANY STRIP-FEEDING MECHANISM FOR SEWING MACHINES Application filed November 26, 1927, Serial No. 235,868, and in Germany December 30, 1926.

The invention relates to new and useful improvements in strip feeding mechanisms for sewing machines, and more particularly to a guiding mechanism wherein a strip is attached at one side edge thereof to a fabric section by stitching.

An object of the invention is to provide a strip uiding mechanism which includes de vices or putting a strip under tension as it passes to the stitching mechanism, wherein said tensioning devices are adapted to be shifted relative to each other to facilitate the insertion of the strip.

A further object of the invention-is to provide a strip guiding mechanism of the above type wherein there are edge guiding members at each side of the strip with spaced rods extending from one edge guiding member to the other, so that a strip may be led over and under the rods and a tension placed thereon, and wherein one of said edge guiding memhers is adapted to be moved relative to the other, and at the same time to move the rods which are above the strip so as to facilitate the insertion of the strip into the strip guiding mechanism.

These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings which show by way of illustration one embodiment of t e invention- Figure 1 is an end view of a portion of a sewing machine showing the improved strip guiding mechanism thereon;

Fig. 2 is a view partly in section along the line of feed, and showing in broken lines the shifting of one of the edge guides and the rods carried thereby;

Fig. 3 is a view partly in plan and partly in section, showing the presser foot and the strip guiding mechanism;

Fig. 4 is a sectional view'on the line AB of Fig. 3, and

Fig. 5 is a side view of the presser foot and strip guiding mechanism showing one of the ed e guidin members raised carrying the rods mounted thereon to position for the insertion of the strip. A

The invention is directed broadly to a strip lowered with the presser bar. It includes a yielding member attached to the main shank of the presser foot and extending in front of said foot so as to form a vertically yielding edge guide for one edge of the strip. Secured to the presser foot at the forward end thereof is a rod which extends in a direction at right angles to the length of feed. Mounted on said rod is a sleeve carrying a second edge guiding member, which is adapted to engage and guide the outer edge of the strip.

Mounted on the edge guiding member disposedat the inner edge of the strip is a guide rod over which the strip passes on its way beneath the presser foot. The other edge guidlng member is provided with two rods which overlie the strip, and when this edge guiding member is turned down into position for guiding the edge beneath the presser foot, these rods move to points beneath the rod first-mentioned, and thus it is that the strip passes underneath the first rod, then up over the second rod, and underneath the third rod, and from this point beneath the presser foot. By mounting certain of the rods on one edge guiding member, and the other rod on the other edge guiding member, and making the outer edge guiding member movable, the rods carried thereby may be lifted, so that the strip may be laid across the lower rod and beneath the foot, after which the outer edge guiding member is lowered, thus bringing the rods carried thereby into position for guiding and putting a tension on the strip.

Referring more in detail to thedrawings, the strip guiding mechanism is shown as applied to a sewing machine which includes a work support 1 and a needle bar 2 carrying a needle or needles 3. The presser bar 4 is provided with a presser foot 5. A fabric section is indicated at 6 in the drawings, and to this fabric section is stitched a strip 7. As shown diagrammatically in Fig. 4, there are two lines of stitching; therefore, there are two needles 3, 3. The needle loops are joined beneath the fabric section by a looper thread. One line of stitching passes through the strip and the fabric section, while'the other passesthrough the strip and past the edge of the fabric section.v This firmly joins the strip to the fabric section and covers the edge of the fabric section. Other types of stitching mechanism might be used without departing from the spirit of the invention.

The presser foot 5 is provided with a shank portion 15 which is secured to the presser bar. This shank portion 15 has a vertical channel formed therethrough at one side of the foot. Located alongside of the foot is a yield ng edge guiding member 8. 'This edge guiding member 8 is rigidly attached to a shank 16 which moves freely in a vertical direction in the channel in the shank 15 of the presser foot. A spring 19 hearing on the upper end of said shank 16 will yieldingly press the edge guiding member 8 into contact with the fabric section. and hold said. edge guiding member positioned beneath the lower face of the presser foot 5, so that it serves as an edge guide to the material all the way across the outer face of the presser foot. A pin 17 carried by the shank 15 passes through an elongated slot 18, and serves as a stop for limiting the downward movement of the shank portion 16 when the presser foot 1s raised from the material.

Mounted on the edge guiding member 8 1s a rod 10. This rod is located at a distance in front of the presser foot, and is at substantial right angles to the line of feed. The rod is supported in a hub formed as a part of the guiding member 8, and a suitable latch may be used for holding the rod in place in the hub. The end of the rod has a knurled head to aid in its removal, if desired.

Mounted on the presser foot 5 is a supporting bar 20. This bar projects to the right of the presser foot, as viewed in Fig. 3. Mounted on the rod 20 is a sleeve 20 which is secured to the rod by a set screw 12. Formed integral with the sleeve 20 is an edge guiding member 9. It will be apparent from Fig. 3 of the drawings, that the strip 7 passes between the edge guiding members 8 and 9, and these edge guiding members cooperate with the respective inner and outer edges of the strip in properly positioning the strip for stitching the same to the fabric section.

Attached to the edge guiding member 9 are two rods 11, 11. These rods are spaced from each other, and they are spaced at a different distance from the front end of the presser foot than the rod 10. The edge guiding member 8 is formed with slots 14, 14, formed on the arc of a circle struck about the center of tre rod 20. The edge guiding member 9 is formed with a slot 13 which is likewise curved about the center of the rod 20. The rods 11 are longer than the distance between the edge guides, and likewise, the rod 10 is guide 9 is in this raised position, the rods 11,

11 are withdrawn from the slots 14, 14. Both of these rods 11 are now above the line pass ing through the rod 10, and beneath the rod 20 at the front end of the presser foot. Thus it is that a strip may be laid under the presser foot and straight across the rod 10, said strip being moved lengthwise of the rod 10 for placing the same, if desired. After the strip has been placed, then the edge guiding memher 9 may be moved down, and the rods 11, 11 will be carried into the segmental slots 14, 14;, while the slot 13 passes down on to the rod 10. lVhen the parts are thus positioned, the strip 7 will pass beneath the rod 11 at the out-- er end of the edge guiding member, thence upwardly over the rod 10, thence substantially downwardly in a vertical direction heneath the inner rod 11, and thence beneath the foot, all as clearly shown in Fig. 2 of the drawings. By this arrangement of the rods, the strip is placed under tension. The amount of tension may be varied by varying the set position of the edge guiding member 9. It will be noted that the rods 11 are set back slightly from the lower edge of this edge guiding member 9, so that the strip passing underneath the rods 11 and over the rod 10, will have its edge properly directed by the edge guiding member 9.

It will be apparent from the above description that if the presser foot is moved up and down by the passing of cross seams or the like, that the tension mechanism will also move up and down with the presser foot, and thus the tension on the strip will not be varied. It will also be obvious from the above description that the strip guiding mechanism may be very quickly positioned so as to facilitate the placing of the fabric strip therein.

It is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters-Patent, is

1. The combination of a presser foot and a strip guiding mechanism carried thereby, said strip guiding mechanism including spaced edge guiding members, one of which is shiftable in a vertical plane relative to the other, rods carried by the edge guiding members and extending from one member to the other, said rods being spaced and arranged so that a strip guided between said members may be led over and under the rods and a tension placed thereon.

2. The combinationof a presser foot and a strip guiding mechanism carried thereby, said strip guiding mechanism including spaced edge guiding members, one of which is shiftable in a vertical plane relative to the other, rods carried by the edge guiding members and extending from one member to the other, said rods being spaced and arranged so that a strip guided-between said members may be led over and under the rods and a tension placed thereon, said rods being of greater length than the distance between the edge guiding members, and said edge guiding members being slotted so as to permit the movable edge guiding member to be shifted with the rods carried thereby.

3. The combination of a presser foot and a strip guiding mechanism carried thereby, said strip guiding mechanism including a yielding edge guiding member projecting in front of the presser foot, a rod extending transversely of the front end of said presser foot, an edge guiding member carried by said rod and projecting in front of the foot, means whereby said last-named edge guiding member may be shifted in a vertical plane, a rod rigidly mounted on the yielding edge guiding member and extending beyond the opposed edge guiding member, rods carried by said opposed edge guiding member and extending across to and beyond the yielding edge guiding member, said edge guiding members being slotted so as to permit the movement of one of said edge guiding members with the rods carried thereby to facilitate the threading of the strip into the strip guiding mechanism. In testimony whereof, I affix my signature.

KARL MAIER. 

